1. Field of the Invention
This invention relates to a probe apparatus and a method for inspecting an object with the use of the probe apparatus.
2. Description of the Related Art
In general, semiconductor devices are assembled after various inspecting processes, and thereafter the basic operational characteristics of the devices are inspected through a burn-in system such as dynamic burn-in. Only good semiconductor devices which passed the electrical inspection are put on the market, and are mounted on printed circuit boards and used for various purposes.
In a general conventional method for mounting a semiconductor device onto a printed circuit board, IC packages are mounted on a printed circuit board, which are obtained by mounting IC chips such as LSIs on lead frames and then packaging the resultants with a resin or a ceramics. Recently, however, a bare chip mounting method has attracted a great deal of public attention. In a system using the method, bare IC chips which are not yet packaged are directly mounted on a board having wiring layers laminated, by the use of a TAB method or a flip chip mounting method, etc.
The bare chip mounting method enables high density mounting and miniaturization since it mounts chips without packages, and also enables high speed calculation as a result of a reduction in wire length. For example, such a bare chip mounting method is spreading, for example of, as a Multi-Chip Module (hereinafter briefly called "MCM").
By virtue of the above advantage, MCMs are considered to be applied from now on to workstations such as CADs, etc., and to more and more spread rapidly. Since the MCM is a system which comprises a multiplicity of IC chips (bare chips) having various functions and provides a predetermined calculating function, electrical inspections are necessary to inspect whether each bare chip can effect its function and also whether the system, a combination of bare chips, can effect the predetermined calculating function.
However, since the MCM itself is a new product, bare chips are not being individually sold, and there is no inspection system for inspecting each bare chip. Therefore, at present, a special inspection system is used to electrically inspect bare chips individually. Good bare chips selected as a result of the inspection are mounted on a board to form an MCM, thereby packaging the MCM to provide a finished MCM product. The finished MCM product is inspected by the use of another inspection system.
In the above-described conventional inspecting system for inspecting finished MCM products, however, it is necessary to transfer the finished MCM products one by one into the inspecting section of the inspection system to electrically inspect them, and thereafter to take them out of the inspecting section. As a result, a great amount of time is necessary to inspect a large number of MCMs. This cannot meet the increasing demand for the inspection of MCMs, which is expected in the near future in accordance with widely spread MCMs.
Further, since in the case of the conventional inspecting system, only a finished product is electrically inspected, it can be deemed defective due to a single defective bare chip incorporated therein. Thus, even good bare chips contained in the finished product deemed defective are casted away together with defective bare chips.